Behaviour of composite joints with concrete encased CFST columns under cyclic loading : experiments

Concrete-encased concrete filled steel tube (CFST) columns have been applied in some real structures in recent years, where they were connected with reinforced concrete (RC) beams or steel beams in a building. Seven composite joint models, including four concrete-encased CFST column to RC beam joints and three concrete-encased CFST column to steel beam joints, were thus tested and compared under constant axial load on the top of the column and cyclic load at the end of the beam. The main test parameters included the joint type, axial load level on the composite column and the existence of the RC slab or not. Based on the test results, the strength, ductility, rigidity degradation, and dissipated energy of the specimens were investigated. It was found that the composite joints displayed favourable seismic performance and might be applicable in earthquake-prone regions.